#include <stdio.h>
#define POS_INFINITY (1.0 / 0.0)
#define NEG_INFINITY (-1.0 / 0.0)
int add(int a, int b)
{
	return a + b;
}

int sub(int a, int b)
{
	return a - b;
}

int mul(int a, int b)
{
	return a * b;
}

double div(int a, int b)
{
	if (b == 0) {
		return a > 0 ? POS_INFINITY : NEG_INFINITY;
	}

	return a / (double) b;
}

int mod(int a, int b)
{
	return a % b;
}

int main(void)
{
	int a, b;
	char op;

	scanf("%d%d", &a, &b);

	do {
		scanf("%c", &op);
	} while (op == ' '); // 忽略空格 

	switch (op)
	{
		case '+':
			printf("两数和为%d\n", add(a, b));
			break;
		case '-':
			printf("两数差为%d\n", sub(a, b));
			break;
		case '*':
			printf("两数积为%d\n", mul(a, b));
			break;
		case '/':
			printf("两数商为%.3lf\n", div(a, b));
			break;
		case '%':
			printf("余数为%d\n", mod(a, b));
			break;
		default:
			printf("不支持'%c'运算\n", op);
	}

	return 0;
}
